1. Field of the Invention
The present invention relates to a hinge for a laptop computer, and the like, which controls angular motion of a display screen with respect to a keyboard base using a frictional force created by an interference fit among compressible elastic washers, the display screen, and the keyboard base.
2. Description of the Related Art
As is generally known, laptop computers include a display screen attached to a keyboard base via a hinge. Examples of such hinges are hinges 1, shown in FIG. 1A, which, for laptop computer 2, attach display screen 3 to keyboard base 4. Such hinges are designed both to permit angular motion of the display screen with respect to the keyboard base, and to maintain the display screen at an angle with respect to the keyboard base absent an applied force.
Conventional hinges for laptop computers and the like are complex in structure, and thus costly to manufacture. For example, some such hinges, such as constant torque hinges, rely on tension created by a band or spring wrapped around a shaft to control angular motion of a display screen. While such arrangements can be effective, as noted, due to their complexity, they are both difficult and costly to manufacture.
Friction hinges, which control angular motion of a display screen with respect to a keyboard base by using friction between portions of the display screen and the keyboard base, are also generally known in the art. Heretofore, however, such friction hinges have relied upon complex mechanisms and arrangements to generate a necessary frictional force.
In this regard, conventional friction hinges most commonly rely upon screws or bolts to generate a frictional force among washers, portions of a keyboard base and a display screen. In such hinges, the frictional force is created by tightening the screw to increase pressure on the washers. While such conventional friction hinges can be effective, they suffer from the same drawbacks as the constant torque hinges described above. That is, conventional friction hinges are both mechanically complex and costly. In addition, conventional friction hinges oftentimes require adjustment at some point during their lifetime due to a loosening of the screw or to general wear.
Thus, there exists a need for a hinge which controls angular motion of a display screen with respect to a keyboard base, which can maintain the display screen at a fixed angle with respect to the keyboard base, and which is both structurally simple and inexpensive to manufacture.